Nowadays, in an IC card with non-contact capability, such as a dual-interface smart card with ID-1 size, the RF antenna loop 111 is always positioned in the chip base 122 of the card, with the two connection points of the antenna loop 111 directly connected with lead wires of the chip 123 of the smart card, as shown in FIG. 1.
As the application of the smart IC card develops, dual-interface smart IC card garners more attention for its double work interfaces and convenient non-contact application mode. Applied in embedded devices such as mobile telephones to realize mobile payment, identity authentication, etc., it will bring much more convenience to our daily lives.
A dual-interface smart card has its unique features in applications of mobile telephones. Take dual-interface SIM card for instance, the contact interfaces get across the SIM neck, and the required working electrical signals such as VCC, CLK and I/O are provided by the mobile telephone. Yet, the non-contact interface of the dual-interface SIM card depends on RF antenna to provide signals such as clock and data for its work. For power signal, the power is provided by VCC when the mobile telephone is on; otherwise, the power is provided by the RF antenna. However, the present scheme that the antenna of ID-1 card is positioned in the chip base cannot meet the application requirement for the embedded devices such as mobile telephones.
Nowadays, the mobile payment scheme based on the mobile phone, which is carried out in countries such as Japan and South Korea, applies the scheme of modifying the mobile phone. The smart IC card with expense payment function is positioned in the mobile phone, and its RF antenna is positioned on the mainboard or backside of the special cell phone battery and connected with the smart IC card via specially designed contact points. This solution has relatively high cost, since it relates to modification of the mobile phone. In the application environment of mobile telecommunications in China, the cost for modification of mobile phones in this method is very evident. The user should purchase a mobile phone with a mobile payment function if he/she wants to use a mobile payment function. Therefore, the utility expense of the user is very high, which would limit the development of mobile payment business.